+ Reply to Thread
Page 1 of 3 123 LastLast
Results 1 to 10 of 26

Thread: Bad Circuit-open Relay Symptoms

  1. #1
    Banned
    THE1JZSPECIAL's Avatar
    Join Date
    Apr 2008
    Location
    South Florida
    Posts
    111

    Default Bad Circuit-open Relay Symptoms

    Just need to clear the air waves with this, what happens when the circuit-open relay goes bad? The car's behavior

  2. #2
    never ending project ...
    di_rosa's Avatar
    Join Date
    Apr 2005
    Location
    toronto
    Posts
    215

    Default Re: Bad Circuit-open Relay Symptoms

    your car won't start. the COR turns on the fuel pump relay and thereby the fuel pump, so if it goes bad, no fuel pump, and therefore no start. a lot of people (including me) have just bypassed this relay. it is meant to only turn the fuel pump on when the car is actually cranking over, hence why it takes a couple of turns to actually start instead of just 1.

    if you hear your fuel pump (after cranking), then it's fine. by bypassing it, it just means your fuel pump is on when your key is in the "on" position. nothing else as far as i know

  3. #3
    Banned
    THE1JZSPECIAL's Avatar
    Join Date
    Apr 2008
    Location
    South Florida
    Posts
    111

    Default Re: Bad Circuit-open Relay Symptoms

    Quote Originally Posted by di_rosa View Post
    your car won't start. the COR turns on the fuel pump relay and thereby the fuel pump, so if it goes bad, no fuel pump, and therefore no start. a lot of people (including me) have just bypassed this relay. it is meant to only turn the fuel pump on when the car is actually cranking over, hence why it takes a couple of turns to actually start instead of just 1.

    if you hear your fuel pump (after cranking), then it's fine. by bypassing it, it just means your fuel pump is on when your key is in the "on" position. nothing else as far as i know
    ok when the car is runing meaning the circuit for relay is now closed, the car iruning fine is it possible for the circuit-open relay to cycle back open the circuit and shut the fuel pump down(when runing) or they dont do that?
    Attached Images Attached Images

  4. #4
    Happy as hell :D
    honestabe's Avatar
    Join Date
    Jan 2006
    Location
    Mount Vernon, WA, USA
    Posts
    3,779
    Blog Entries
    2

    Default Re: Bad Circuit-open Relay Symptoms

    I've done the bypass so that I've manually turned on the fuel pump my jumping it at the diagnostic port and the car still has the same issue.
    Project Clean 87 Build Thread
    http://www.supramania.com/forums/showthread.php?t=40754

    Engine built and tuned by Bill Bowering @ Independent Speed Shop in Langley, B.C.
    http://indy-speed.com/

  5. #5
    never ending project ...
    di_rosa's Avatar
    Join Date
    Apr 2005
    Location
    toronto
    Posts
    215

    Default Re: Bad Circuit-open Relay Symptoms

    well, according to the wiring diagrams i've looked it seems that if you pull the relay out, the fuel pump relay will not have power, and therefore won't turn the fuel pump on, so if that is possible, then yeah, the relay can fail and not turn it on..........but shutting off while running, i dunno, that's weird.

    it might be easier to just bypass the relay like i was saying, and see if the problem goes away?

  6. #6
    never ending project ...
    di_rosa's Avatar
    Join Date
    Apr 2005
    Location
    toronto
    Posts
    215

    Default Re: Bad Circuit-open Relay Symptoms

    who's the one with the problem?

    wanna give some more info of what exactly happens?

  7. #7
    Banned
    THE1JZSPECIAL's Avatar
    Join Date
    Apr 2008
    Location
    South Florida
    Posts
    111

    Default Re: Bad Circuit-open Relay Symptoms

    Quote Originally Posted by honestabe View Post
    I've done the bypass so that I've manually turned on the fuel pump my jumping it at the diagnostic port and the car still has the same issue.
    yea I know your problem is the ECU, But when I crank that soja boy I get no fuel at times.

  8. #8
    Happy as hell :D
    honestabe's Avatar
    Join Date
    Jan 2006
    Location
    Mount Vernon, WA, USA
    Posts
    3,779
    Blog Entries
    2

    Default Re: Bad Circuit-open Relay Symptoms

    Both me and Special are having a problem. Mine will try and crank and will reach about 500 RPM's while cranking, and almost fire (sounds like one or two of the cylinders is starting to fire), but then no fire. If it does fire up, it'll fire up just fine and run perfectly for a couple seconds and even be able to be revved up but then die and refuse to restart. Already checked the igniter today with a brand new one.
    Project Clean 87 Build Thread
    http://www.supramania.com/forums/showthread.php?t=40754

    Engine built and tuned by Bill Bowering @ Independent Speed Shop in Langley, B.C.
    http://indy-speed.com/

  9. #9
    Banned
    THE1JZSPECIAL's Avatar
    Join Date
    Apr 2008
    Location
    South Florida
    Posts
    111

    Default Re: Bad Circuit-open Relay Symptoms

    Quote Originally Posted by di_rosa View Post
    well, according to the wiring diagrams i've looked it seems that if you pull the relay out, the fuel pump relay will not have power, and therefore won't turn the fuel pump on, so if that is possible, then yeah, the relay can fail and not turn it on..........but shutting off while running, i dunno, that's weird.

    it might be easier to just bypass the relay like i was saying, and see if the problem goes away?
    ok I was bypassing it but with the relay off, i haven't tried with the relay on

  10. #10
    never ending project ...
    di_rosa's Avatar
    Join Date
    Apr 2005
    Location
    toronto
    Posts
    215

    Default Re: Bad Circuit-open Relay Symptoms

    Quote Originally Posted by THE1JZSPECIAL View Post
    ok I was bypassing it but with the relay off, i haven't tried with the relay on
    what do you mean with the relay off? i assume you pulled the COR and put in a thick gauge piece of wire to jump it and then try to start it? did you confirm you did it correctly by listening for the fuel pump when the key is "on" ?



    do either of you know for sure that you have stable fuel pressure from like a gauge? do you hear your fuel pump all through the cranking?

    have you checked for codes? spark?

+ Reply to Thread
Page 1 of 3 123 LastLast

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
Links monetized by VigLink